Previous work in our laboratory has explored the effects of alcohol on the aggressive behavior of mice, rats and squirrel monkeys. We have found an interesting interaction between testosterone and the effect of alcohol on behavior. We have also begun to analyse some of the social dynamics which modify alcohol response. There are three main objectives of the present proposal: (l) an analysis of the mechanism of testosterone's ability to alter differentially the aggression-heightening and -inhibiting effects of alcohol in males and females; (2) to investigate the role of social status and experience as determinants of alcohol's effect on aggressive behavior; (3) to assess the effects of self-administered compared to force-administered alcohol on social behavior. The use of quantitative ethological methodology in this proposal will provide a more reliable and complete analysis of several dimensions of behavior, including the sequencing and patterning of species-typical behavior as well as pathological behavior. This methodology will be used to further quantify the effect of alcohol in situations which reliably engender attack, threat, defense, submission, flight and other agonistic and non-agonistic behaviors. Three experiments will focus on objective l. They will investigate: a) the role of sexual differentiation in determining sensitivity to the effect of testosterone on alcohol response, b) the neural sites of the testosterone-alcohol interaction on aggressive behavior, and c) the importance of metabolism of testosterone to estradiol and/or dihydrotestosterone as part of its mechanism of action. Two experiments will focus on objective 2. The first will vary social status within groups of animals and determine possible changes in sensitivity to alcohol and corresponding changes in endocrine activity. The second will examine the effect of aggressive or defeat experience on the later behavioral and endocrine response to acohol. The final experiment will focus on objective 3 and study the effect of self-administration of low, aggression-heightening doses of alcohol on behavior. Our goal is to learn more about the effect of alcohol on the central nervous system and behavior. We believe that the study of alcohol, hormones and social behavior in animals may help clarify the mechanisms which control the effects of alcohol on aggression in humans.